Observer-based clutch disengagement control during gear shift process of automated manual transmission

Abstract

A clutch disengagement strategy is proposed for the shift control of automated manual transmissions. The control strategy is based on a drive shaft torque observer. With the estimated drive shaft torque, the clutch can be disengaged as fast as possible without large driveline oscillations, which contributes to the reduction of total shift time and shift shock. The proposed control strategy is tested on a complete powertrain simulation model. It is verified that the system is robust to the variations of driving conditions, such as vehicle mass and road grade. It is also demonstrated that the revised system with switched gain can provide satisfactory performance even under large estimation error of the engine torque.

Keywords:

• automated manual transmission
• clutch disengagement control
• shift quality
• shaft torque estimation

Acknowledgements

This work is supported by the National Science Fund of China for Distinguished Young Scholars (60725311), the National Science & Technology Major Project (2009ZX01038-002-001) and the National Natural Science Foundation of China (50505014).